From e55945e219dbf4664683a757c5a9d462c98f2e19 Mon Sep 17 00:00:00 2001
From: Romain Guy <romainguy@google.com>
Date: Thu, 4 Apr 2013 15:26:04 -0700
Subject: [PATCH] Reduce the size of dirty invalidates

Remove remnants from times long gone. We don't need to redraw the
union of the previous frame's dirty region and the new dirty
region.

Change-Id: I9fb96f99a6a72c2233f9ca563cf6432a42b2b65b
---
 core/java/android/view/HardwareRenderer.java | 15 +++----------
 core/java/android/view/ViewRootImpl.java     | 23 +++++++++-----------
 2 files changed, 13 insertions(+), 25 deletions(-)

diff --git a/core/java/android/view/HardwareRenderer.java b/core/java/android/view/HardwareRenderer.java
index 7918823bf583f..8055077d58b90 100644
--- a/core/java/android/view/HardwareRenderer.java
+++ b/core/java/android/view/HardwareRenderer.java
@@ -451,10 +451,8 @@ public abstract class HardwareRenderer {
      * @param attachInfo AttachInfo tied to the specified view.
      * @param callbacks Callbacks invoked when drawing happens.
      * @param dirty The dirty rectangle to update, can be null.
-     * 
-     * @return true if the dirty rect was ignored, false otherwise
      */
-    abstract boolean draw(View view, View.AttachInfo attachInfo, HardwareDrawCallbacks callbacks,
+    abstract void draw(View view, View.AttachInfo attachInfo, HardwareDrawCallbacks callbacks,
             Rect dirty);
 
     /**
@@ -992,11 +990,7 @@ public abstract class HardwareRenderer {
                             mCanvas = createCanvas();
                             mCanvas.setName(mName);
                         }
-                        if (mCanvas != null) {
-                            setEnabled(true);
-                        } else {
-                            Log.w(LOG_TAG, "Hardware accelerated Canvas could not be created");
-                        }
+                        setEnabled(true);
                     }
 
                     return mCanvas != null;
@@ -1340,7 +1334,7 @@ public abstract class HardwareRenderer {
         }
 
         @Override
-        boolean draw(View view, View.AttachInfo attachInfo, HardwareDrawCallbacks callbacks,
+        void draw(View view, View.AttachInfo attachInfo, HardwareDrawCallbacks callbacks,
                 Rect dirty) {
             if (canDraw()) {
                 if (!hasDirtyRegions()) {
@@ -1401,11 +1395,8 @@ public abstract class HardwareRenderer {
                     }
 
                     attachInfo.mIgnoreDirtyState = false;
-                    return dirty == null;
                 }
             }
-
-            return false;
         }
 
         private DisplayList buildDisplayList(View view, HardwareCanvas canvas) {
diff --git a/core/java/android/view/ViewRootImpl.java b/core/java/android/view/ViewRootImpl.java
index 7b34ce1cff958..b72a30b27e8e8 100644
--- a/core/java/android/view/ViewRootImpl.java
+++ b/core/java/android/view/ViewRootImpl.java
@@ -197,7 +197,6 @@ public final class ViewRootImpl implements ViewParent,
     int mHeight;
     Rect mDirty;
     final Rect mCurrentDirty = new Rect();
-    final Rect mPreviousDirty = new Rect();
     boolean mIsAnimating;
 
     CompatibilityInfo.Translator mTranslator;
@@ -767,10 +766,11 @@ public final class ViewRootImpl implements ViewParent,
 
                 final boolean translucent = attrs.format != PixelFormat.OPAQUE;
                 mAttachInfo.mHardwareRenderer = HardwareRenderer.createGlRenderer(2, translucent);
-                mAttachInfo.mHardwareRenderer.setName(attrs.getTitle().toString());
-                mAttachInfo.mHardwareAccelerated = mAttachInfo.mHardwareAccelerationRequested
-                        = mAttachInfo.mHardwareRenderer != null;
-
+                if (mAttachInfo.mHardwareRenderer != null) {
+                    mAttachInfo.mHardwareRenderer.setName(attrs.getTitle().toString());
+                    mAttachInfo.mHardwareAccelerated =
+                            mAttachInfo.mHardwareAccelerationRequested = true;
+                }
             } else if (fakeHwAccelerated) {
                 // The window had wanted to use hardware acceleration, but this
                 // is not allowed in its process.  By setting this flag, it can
@@ -2385,14 +2385,10 @@ public final class ViewRootImpl implements ViewParent,
                 mResizeAlpha = resizeAlpha;
 
                 mCurrentDirty.set(dirty);
-                mCurrentDirty.union(mPreviousDirty);
-                mPreviousDirty.set(dirty);
                 dirty.setEmpty();
 
-                if (attachInfo.mHardwareRenderer.draw(mView, attachInfo, this,
-                        animating ? null : mCurrentDirty)) {
-                    mPreviousDirty.set(0, 0, mWidth, mHeight);
-                }
+                attachInfo.mHardwareRenderer.draw(mView, attachInfo, this,
+                        animating ? null : mCurrentDirty);
             } else {
                 // If we get here with a disabled & requested hardware renderer, something went
                 // wrong (an invalidate posted right before we destroyed the hardware surface
@@ -2447,6 +2443,8 @@ public final class ViewRootImpl implements ViewParent,
 
             canvas = mSurface.lockCanvas(dirty);
 
+            // The dirty rectangle can be modified by Surface.lockCanvas()
+            //noinspection ConstantConditions
             if (left != dirty.left || top != dirty.top || right != dirty.right ||
                     bottom != dirty.bottom) {
                 attachInfo.mIgnoreDirtyState = true;
@@ -3097,8 +3095,7 @@ public final class ViewRootImpl implements ViewParent,
                         boolean inTouchMode = msg.arg2 != 0;
                         ensureTouchModeLocally(inTouchMode);
 
-                        if (mAttachInfo.mHardwareRenderer != null &&
-                                mSurface != null && mSurface.isValid()) {
+                        if (mAttachInfo.mHardwareRenderer != null && mSurface.isValid()){
                             mFullRedrawNeeded = true;
                             try {
                                 mAttachInfo.mHardwareRenderer.initializeIfNeeded(